From: Daniel Borkmann <daniel@iogearbox.net>
To: Alexei Starovoitov <ast@kernel.org>, davem@davemloft.net
Cc: peterz@infradead.org, jannh@google.com, paulmck@linux.ibm.com,
will.deacon@arm.com, mingo@redhat.com, netdev@vger.kernel.org,
kernel-team@fb.com
Subject: Re: [PATCH bpf] bpf: run bpf programs with preemption disabled
Date: Thu, 31 Jan 2019 23:24:19 +0100 [thread overview]
Message-ID: <a2338f78-8f0c-2cdb-f040-bf0040ca6522@iogearbox.net> (raw)
In-Reply-To: <20190129024334.1100196-1-ast@kernel.org>
On 01/29/2019 03:43 AM, Alexei Starovoitov wrote:
> Disabled preemption is necessary for proper access to per-cpu maps
> from BPF programs.
>
> But the sender side of socket filters didn't have preemption disabled:
> unix_dgram_sendmsg->sk_filter->sk_filter_trim_cap->bpf_prog_run_save_cb->BPF_PROG_RUN
>
> and a combination of af_packet with tun device didn't disable either:
> tpacket_snd->packet_direct_xmit->packet_pick_tx_queue->ndo_select_queue->
> tun_select_queue->tun_ebpf_select_queue->bpf_prog_run_clear_cb->BPF_PROG_RUN
>
> Disable preemption before executing BPF programs (both classic and extended).
>
> Reported-by: Jann Horn <jannh@google.com>
> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Applied, thanks!
prev parent reply other threads:[~2019-01-31 22:24 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-29 2:43 [PATCH bpf] bpf: run bpf programs with preemption disabled Alexei Starovoitov
2019-01-29 7:01 ` Song Liu
2019-01-31 22:24 ` Daniel Borkmann [this message]
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